Foamed adhesives can be generated by the creation of gas-filled voids in an adhesive matrix (e.g., by means of a blowing agent) and are particularly desirable in applications requiring high peel strength. Foamed adhesives have a variety of additional advantageous properties, such as low consumption of adhesive, and high tack and bond strength. The elasticity and plasticity of the foamed adhesive compositions make articles including foamed adhesive layers highly conformable, even on uneven surfaces.
However, the placement and size of the gas-filled voids within the adhesive matrix is difficult to control. Due to the imprecise nature of the blowing process, it is not possible to precisely control the total void volume within the adhesive matrix. In addition, the ratio of adhesive matrix relative to the total void volume is relatively low, which renders this foam-based adhesives unsuitable in certain applications requiring very thin constructions.